<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>旋转</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }
        .outer {
            width: 200px;
            height: 200px;
            border: 2px solid black;
            margin: 0 auto;
            margin-top: 100px;
        }
        .inner {
            width: 200px;
            height: 200px;
            background-color: skyblue;
            /*3d,x,y一起才是3d,z是2d,因为x,y是2d,所以要绕z旋转，单位deg*/
            /*沿着元素正中央旋转*/
            transform: rotateZ(30deg);
        }

    </style>
</head>
<body>
<div class="outer">
    <div class="inner">
        你好啊
    </div>
</div>

</body>
</html>